Support structure for folding tables and like structures

Abstract

A folding table or like structure having a generally planar top supported on the floor by four or more legs, a support structure comprising: two points of articulation under the underside of the table top located at some distance inward from the edge of the table; two splayed legs in V-formation extending from each point of articulation to a point on the floor approximately vertically below the corner of the table top; a cable network interconnecting the lower ends of said legs; and a second series of cables extending from each corner of the table top to the lower end of the leg located below the respective corner, the arrangement being such that in the assembled state all cables are in tension and the legs are in compression.

What I claim is: 
     
       1. In a folding table or like structure having a generally planar table top supported on the floor by multiple legs, a support structure comprising: (1) multiple points of articulation located below the table top at some distance inward from the edge of the table, at least two of said points being spaced apart from each other;   (2) two splayed legs in V-formation extending each from each point of articulation to points on the floor approximately vertically below the corners of the table top;   (3) a cable network interconnecting the lower ends of said legs and extending from each corner of the table top to the lower end of the leg located vertically below the respective corner; the arrangement being such that in the assembled state all cables are in tension and the legs are in compression.     
     
     
       2. A folding table as claimed in claim 1, wherein the cable network interconnecting the lower ends of the legs forms a double Y with a central member having two ends and extending vertically below the longitudinal axis of the table top and two pairs of members diverging from the two ends respectively of the central member, which ends are disposed vertically below the two spaced articulation points respectively. 
     
     
       3. A folding table as claimed in claim 1, wherein the cable network interconnecting the lower ends of the legs forms a rectangle. 
     
     
       4. A folding table as claimed in claim 1, wherein the legs and the cables extending from each corner of the table to the lower end of the nearest leg form a series of triangles which give the table stability and eliminate wobble. 
     
     
       5. A folding table as claimed in claim 1, wherein the table top is a rectangular flexible solid and the points of articulation are located on the underside of the table top inward from the narrow ends of the table top by a distance which is approximately equal to one sixth of the total length of the table top. 
     
     
       6. A folding table as claimed in claim 1, wherein the table top is pre-formed with a slight camber so that when under stress the tension forces exerted by the vertical cables will cause the table top to assume an essentially flat configuration. 
     
     
       7. A folding table as claimed in claim 5, wherein the points of articulation on the underside of the table are arranged to be pushed away from each other and in this manner the cables are put under tension. 
     
     
       8. A folding table as claimed in claim 7, wherein the points of articulation slide in guides on the underside of the table top and are connected by a pair of hinged struts. 
     
     
       9. A folding table as claimed in claim 1, wherein the points of articulation are fixed on the underside of the table top and the structure is brought under tension by pulling the lower ends of the legs towards each other. 
     
     
       10. A folding table as claimed in claim 2, wherein the central member of the double Y-shaped cables interconnecting the lower ends of the legs includes a release means and spring means to apply tension to the cables and compensate for slight changes in lengths due to temperature differences. 
     
     
       11. A folding table comprising: (1) a generally planar loosely supported rigid table top;   (2) two points of articulation located below the underside of the table top approximately midway between the plane of the table top and the floor;   (3) an upper and a lower pair of splayed legs in V-formation extending from each point of articulation; the ends of the lower legs resting on the floor and the ends of the upper legs supporting the table top;   (4) a generally horizontal bar extending between the points of articulation and generally parallel to the table top;   (5) lower cables interconnecting the lower ends of said legs, vertical cables extending generally from the upper ends of the upper legs to the lower leg ends of the lower legs; and upper cables interconnecting the upper ends of said legs.   (6) force release means to bring the cables under tension; the arrangement being such that in the assembled state all the cables are in tension and the legs are in compression.   
     
     
       12. A folding table as claimed in claim 11 comprising a third pair of splayed legs extending in V-formation from each point of articulation towards points of attachment substantially midway along the longer runs of the upper cables, and an additional set of cables extending from said midway points of attachment along the upper cables to a central meeting point of the lower cables located slightly above the level of the floor. 
     
     
       13. A folding table as claimed in claim 11, wherein the horizontal bar extending between the points of articulation is adjustable in length. 
     
     
       14. A folding table as claimed in claim 11, wherein the horizontal bar is in two pieces, one sliding telescopically within the other. 
     
     
       15. A folding structure for use as camping table or bed comprising: (1) a generally rectangular top made from flexible material including canvas and other sheet material;   (2) two points of articulation located below the underside of the top approximately midway between the plane of the top and the ground;   (3) an upper and a lower pair of splayed legs in V-formation extending from each point of articulation; the ends of the lower legs resting on the ground and the ends of the upper legs engaging the top;   (4) a generally horizontal bar extending between the points of articulation and generally parallel to the top;   (5) lower cables interconnecting the lower ends of said legs and vertical cables extending from the upper ends of the upper legs to the lower ends of the lower legs; and upper cables interconnecting the upper ends of said legs;   (6) force release means to bring the cables under tension; the arrangement being such that in the assembled state all the cables are in tension and the top is stretched drum tight between the upper ends of the upper pair of legs.     
     
     
       16. A folding structure as claimed in claim 15 comprising a third pair of splayed legs extending in V-formation from each point of articulation towards points of attachment substantially midway along the longer sides of the top. 
     
     
       17. A folding structure as claimed in claim 15, wherein the horizontal bar extending between the points of articulation is adjustable in length. 
     
     
       18. A folding structure as claimed in claim 17, wherein the horizontal bar is in two pieces, one sliding telescopically with the other. 
     
     
       19. A folding structure as claimed in claim 15, wherein the points of articulation are in the form of a semi-rigid body consisting of a central piece with a number of stubs on which the struts are detachably mounted.